Electric cut-out



April 10; 1928.

G. R. BROWN ELECTRIC CUT-OUT Filed Sept. 17, 1925 Inventor": George R. Brown, Joy His Attorney.

Patented Apr. 10, 1928,

Uhll'llllill S'lA'lliS PATENT (ll l' 'ltfhl.

GEORGE E. BROW'N, {IF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPGRATIOH OF NEW YGEK.

ELECTRIC CUT-OUT.

Application filed September The present invention relates to electric cut-outs and more especially to cut-outs of the plug type.

It is common practice to employ the three wire system for supplying electric current for ordinary house lighting purposes, one wire being neutral between thepotcntials ot the other two. The fuse blocks or out-outs employed for protecting such systems have quite unitormly been provided with three plug receptacles, one for each circuit wire. altl'iougl'i the neutral wire was regarded as carrying no voltage and no current. Today it is believed to be better pract'ce to directly ground the neutral wire, and in order to malie such grounded connection of the neutral wire etlective, it is neces ary that all sections thereof either be COHHQCUGCl together or else all sections thereof individually grounded.

The object of my invention is the provision of a sealing; plug whereby the three wire cut-out blocks now installed inay have their neutral line contacts pci'n'ianently con nected by merely screwiiur it home in the neutral receptacle.

One embodimentof my invention is shown in the accompanying drawing: in which l ie'. l is a plan view of a three wire cut-out block with my sealing plug in place; Fig. 2 is an axial section ot the sealing plug detached; and Fin. 3 is an isometric persg'iectivc ot the same.

lhe cut-out block shown in Fig. 1 1s a well known article of coi'nn'ierce and comprises a porcelain base 1 with three receptacles 2, 3 and t on its upper face and in each receptacle are a screw shell contact 5 and a center contact (5 respectively provided with binding post extensions 7 and S for couplingot' the sections of the line wires thereto. The screw shell contact 5 and the center contact 6 are spaced out of normal conductive relation and requiring ordinarily to be connected by the insertion of a fuse plug (not shown), whereby the current is directed through the fusible element thereof. The contacts 5 and 6 of the middle or neutral receptacle 3 are positively connected 17, 1925. Serial No. 57,037.

electrically by screwing home therein the sealing plug shown detached in Figs. 2 and b.

The plug; comprises a sheet metal thiinble 9 with its cylii'idrical wall threaded corre- :-:poniilin r' to the threaded terminal 5 and its lower end 10 flat and unpunched so that when the plug: is screwed into the threaded tern'iinal electric contact is made therewith through the sides of the plug and through the lower end 10 engaging the center contact 6. 1 v

The means for facilitating the insertion of the. scaling plug and preventing its removal cons' ot a metal disk 11 secured inside tlun'eml and provided with two spaced and oppositely directed teeth 12 struck up therefrom whereby two abrupt shoulders 13 :2 presented for engagement with a screw driver when turned right-l1andedly and cause. the plug to be screwed home, but by reason of the inclines 14; on the opposite sir: ot the teeth, turning of the screw driver left-handedly does not cause a backing out of the plug since there is no coupling engagement between them. The toothed disk 11 is held in the plug thiinblc 9 by solder or by :trictional contact between the parts.

While I have shown the best einbodiniient ot the invention known to me, 1 do not desire to be restricted thereto.

ll hat I. claim as new and desire to secure by Letters Patent of the United States, is:

A sealing; plug for electric cut-outs comprising a scrowtln'eaiiled metal thiu'ible adapted to make shunting contact between he center and screw shell contacts of a cut-ont and a metal disk provided with oppositely inclined spaced teeth securi-zd at the inner end of said thiinblc whereby it may be operated by a screw driver into permanently fixed operative position in said screw shell contact.

In witness whereof, I have hereunto set my hand this eleventh day of September 1925.

GEORGE R: BROWN. 

